Conduction system pacing: comparing technical and clinical outcomes with lumenless versus stylet-driven leads

Abstract Background Conduction system pacing (CSP) ensures physiologic ventricular activation. Growing experiences on applicability are rising. Different available sheaths allow to implant both lumenless (LLL) and stylet-driven (SDL) leads. Objective To analyse implant success rate and different technical and clinical outcomes comparing LLL and SDL. Methods 1033 patients (mean age 78±8 years; 62% males) received CSP from January 2019 to April 2024. In 304 patients His bundle pacing (29%) was performed while 729 patients received left bundle branch area pacing (71%). The choice between LLL and SDL was left to the operator preference. Pacing indication were: AV block 50%, SND 12%, slow AF 12%, ablate&pace 9%; HF 14%, revision of previous lead 1%. Coronary disease was present in 31%; hypertension in 93%, diabetes in 30%, severe valvular disease in 5%, persistent AF in 27% pts. Average QRS duration was 127±36 ms. Basal mean EF 52±13%. Results LLL was utilized in 69% of cases while SDL in the remaining 31%. Similar rate of hypertension, diabetes, ischemic etiology, and atrial fibrillation were found in the two groups; while the group implanted with SDL showed significantly lower ejection fraction (LLL 57±10%; SDL 45±15%; P 0,001) and more dilated heart. Procedural success rate was reached in 95.6% cases and did not differ in SDL compared to LLL (P 0.213). Mean V6RWPT and mean R6-R1 interpeak intervals were similar (P 0.769 and P 0,122 respectively). Nevertheless, the SDL group showed higher procedural (P 0.041) and fluoroscopy time (P 0.038). In the SDL group was more frequent the need for screwing in more than 1 intraseptal position (P 0.000), need for intraprocedurally change of the sheath (P 0.000) or of the lead (P 0.000). Electrical parameters were highly favourable in all patients (mean threshold 0.73±0.27V and mean sensing 11±5.8 mV) without differences between the 2 groups. Paced QRS duration was 114±15 ms (112±14 vs 116±16 ms; P 0.180). Conclusion CSP can be successfully obtained with both LLL and SDL without differences in procedural success rate. SDL procedures required longer procedural and fluoroscopy times and more frequent need for change the sheath or the lead intraprocedurally. Clinical outcomes, named HF hospitalizations, did not differ in the two groups.